Apparatus and process for spraying liquids and producing very fine mist

ABSTRACT

The invention relates to an apparatus and a process for spraying liquids and producing very fine mist, where the apparatus comprises a needle injector, a liquid supply ( 5 ) and a gas supply ( 4 ). The needle injector comprises at least one capillary line ( 1 ) and at least one outer tube ( 8 ), where the capillary line ( 1 ) is arranged in the interior space of the outer tube ( 2 ) and the internal diameter of the capillary line in the needle injector is in the range of 2-1000 μm, preferably in the range of 4-300 μm, more preferably in the range of 5-250 μm. The capillary line is in active communication with a gas supply ( 4 ) and the outer tube ( 2 ) is in active communication with a liquid supply ( 5 ). A spray mist which comprises the liquid in the form of very finely dispersed droplets of 10-20 μm and has a low flow velocity is produced by means of the process of the invention. The properties of the spray mist can be controlled very well via the configuration of the apparatus and the experimental parameters. A preferred field of use of the apparatus is the controlled introduction of spray mists into reaction apparatuses for the study of catalysts or in impregnation apparatuses for the deposition of liquids.

The invention relates to an apparatus and a process for spraying liquidsand producing very fine mist.

A field of application of the invention is in the field of catalystresearch and catalyst testing setups on the laboratory scale, in whichliquid starting materials are brought into contact with catalysts inorder to react the former under controlled conditions. The improvementof laboratory methods is of great economic and industrial importancesince it enables significantly cheaper experimental data to be obtainedthan is the case for pilot plants and production plants. Further fieldsof application relate to the wetting and impregnation of pulverulentsupport materials with liquids. The liquids or the impregnation solutioncan comprise active components or active compounds in dissolved formwhich can be applied to the solids by means of the process according tothe invention. The surface properties of the pulverulent solids can thusbe modified in a controlled manner.

A big industrial challenge in the catalytic conversion of feedstocks influidized catalyst beds then arises if the starting materials aredifficult to handle. This is then in particular the case if the startingmaterials are oils or even heavy oils, which are difficult to process.The most important process for processing petroleum and vacuum gas oils(VGOs) in industry is the conversion thereof in the FCC process, i.e.the fluid catalytic cracking process. The vacuum gas oils originate fromthe vacuum distillation of petroleum, in which the low boilers areremoved. The process using FCC catalysts is carried out in riserreactors in which catalyst streams composed of catalyst particles andgas are brought into contact with oil and reacted. The catalystparticles have an average particle size in the range from 60 to 100 μm(or from 60 to 150 μm). The reactions proceed at temperatures above495-565° C., with the contact times being 20 seconds and less.Medium-sized FCC plants have a charge comprising 100-200 metric tons ofcatalyst, with a catalyst stream of 0.5 to 2 t/h circulating in theseplants.

In particular, the examination of FCC catalysts in laboratory catalysttesting setups is also of great industrial importance. In the case oflaboratory catalyst testing setups, a distinction is to be made betweenthose test setups in which the catalysts are tested in a fixed bed andthose in which the catalysts are tested in fluidized catalyst beds.Examination of catalysts in fixed beds is suitable when from 0.5 to 5 gof catalysts per catalytic cracking experiment is available. In the caseof fluidized catalyst beds, a further distinction is to be made betweenstatically fluidized beds and dynamically fluidized beds. As an exampleof fixed-bed testing, reference may be made to the ASTM method No. ASTMD-3907-86.

As an example of the examination of FCC catalysts in staticallyfluidized catalyst beds, mention may be made of the catalyst testingapparatus disclosed by John Kayser in U.S. Pat. No. 6,069,012. Theamount of catalyst used here for each catalytic cracking experiment isin the range from 5 to 12 g.

An example of test setups with dynamically fluidized catalyst beds isthe micro-downer unit disclosed by Corma et al. in ES 2187387. Thecatalyst stock vessel can, depending on the design, accommodate anaverage of from 100 to 500 g of catalyst. The catalyst has a flow rateof from 10 to 100 g per minute. In a publication by Corma et al. (inApplied Catalysis A: General 232 (2992) pp. 247-263), a schematicdepiction of a reactor for examining FCC catalysts, which is equippedwith a downcomer tube reactor, is given. The oil is sprayed into thereactor by means of an injector, with the oil feed being supplied bymeans of an injection pump. The feed line for the oil is also connectedto a gas line so that either oil feed or gas feed can be introduced intothe injector as desired.

As regards the oil injector, the laboratory catalyst testing setupsoften have an aspect in common, namely that the oil injector disclosedin U.S. Pat. No. 6,069,012 consists of two tubes, with a smaller innertube being passed through a larger outer tube. The oil is then sprayedthrough the small inner tube into the reaction space, with a gas streambeing conveyed through the outer tube at the same time. The collision ofthe oil stream with the gas stream results in partial mixing. The gasstream is started before introduction of the oil feed stream and is onlystopped after the oil flow has been stopped, so that the formation ofoil residues at the ends of the tubes is avoided. The amounts of oil tobe injected per experiment are in the range from 0.5 to 5 ml. Oilinjection is usually carried out by means of injection pumps. Toquantify the amount of oil, the injection pumps can optionally beweighed or subjected to a calibration.

Various apparatuses and processes for atomizing liquids, which can beemployed in various industrial fields, have been described in the priorart. An example which may be mentioned is the production of spray mistsas samples for analytical examinations, the application of surfacecoatings by spray processes and also the work-up of crude oils. In thefollowing, some apparatuses and processes for producing spray mists willbe briefly presented in more detail.

The U.S. Pat. No. 6,241,159 B1 by A. Alfonso Ganán-Calvo et al., whichwas filed on Aug. 16, 2000, describes and claims a process for atomizingliquids, in which suitable geometric parameters and physical propertiesare used in order to ensure that the liquid is released in the form of acontinuous laterally capillary-like microjet through an orifice plate.The process is based on the ejection effect which results from aliquid-gas interface when the gas is ejected at a point in the vicinityof the liquid surface. The process of the invention can be applied toall processes which concern the homogeneous atomization of liquids. Onefield of application is the electronic injection of fuel. In theprocess, the liquid is passed through a first channel and ejected fromthis in the form of a jet. The ejected liquid is entrained by a gas jetand is conveyed together with the latter through an orifice.

The U.S. Pat. No. 6,142,457 by Holtan et al., which was filed on Jan.30, 1998, relates to a spray nozzle and a method of atomizing liquidfeeds. In particular, the invention relates to a method of atomizinghydrocarbon-comprising feeds which are fed into the catalytic crackingzone of fluid catalytic cracking (FCC) processes. The nozzle comprises aprimary passage by which a liquid stream is taken up and a secondarypassage by which a diluent medium is taken up. The diluent medium andthe liquid stream are combined in a mixing zone which is localizedbetween the outlet of the first passage and the outlet of the secondpassage. The hydrocarbon-comprising feed is, in this method, conveyedthrough that passage which is located in the interior of the nozzle. Thediluent medium is conveyed through the annular space arranged betweeninner and outer passage.

The US patent application US2011/0203973 by Li et al., which was filedon Feb. 23, 2010, relates to a process in which dispersions composed ofsupercritical liquid and oil are used in order to work up thehydrocarbon-comprising feeds which, for example, consist of heavy oils.The process is based on the use of a capillary mixer to producedispersions. The capillary mixer comprises a capillary in the interiorof the mixer, through which the oil is conveyed. The capillary in theinterior space and also the tip of the capillary are surrounded by thesupercritical liquid which flows in the same direction as the oil in theinterior of the capillary. In order to achieve a very high throughput,which is necessary for the work-up of oils, it is necessary to use alarge number of capillary mixers simultaneously in a parallelarrangement. Li et al. indicate that, in a preferred embodiment, 100 oreven 1000 capillary mixers can be operated in parallel.

The US patent application U.S. Pat. No. 5,868,322 by Loucks Jr. et al.filed on Sep. 27, 1996 describes an apparatus for producing liquiddroplets which comprises a mechanically fixed inner microtube conduit.The liquid droplets in the form of microscopically fine mist dropletsmay be utilized for producing samples which are subjected to asubsequent analysis. This can constitute MS, AA, ICP, CE/MS or similaranalytical methods. The apparatus has a mechanically stabilizedmicroconduit, through which the liquid is conveyed, in the interior. Theouter conduit which encloses the inner microconduit has a constrictionat the tip.

In the PCT application WO 2014/099312 A1, Anthony Mennito et al.describe an analytical method for characterizing saturated components ofpetroleum or hydrocarbons by means of mass spectroscopic processes whichcomprise high-boiling components and in which ionization by means oflaser desorption is utilized. The introduction of the petroleum sampledissolved in toluene is effected through a syringe needle having amicrosyringe, with the syringe needle being heated. To produce a veryfine mist, nitrogen-comprising gas is introduced as cofeed from a heatedsteel needle. Further desolvation is effected by countercurrent flow ofa stream of nitrogen.

The German patent application DE 10 2007 054 949 A1 by Schimkus et al.,which was filed on Nov. 17, 2007, relates to a spray gun having a doublecannula for spraying paints. The double cannula forms a spray lance,with the liquid paint or surface coating being conveyed through theinner capillary and the gas being conveyed through the outer tube of thespray lance. It can be seen from FIG. 2 that the circular end face ofthe inner capillary and the annular end face of the outer tube are inone plane. As an advantage of the spray lance, it is also mentioned thatthe lance can be angled or curved, which allows the application of paintto be carried out in a controlled manner at places in which spatialaccessibility is limited.

Furthermore, the German patent application DE 10 2010 012 555 A1 byProf. Peter Walzel filed on Mar. 23, 2010 relates to a two-fluid innermixing nozzle arrangement and a process for the atomization of liquids.The nozzle according to the invention makes it possible to produce spraymists having small droplet dimensions, which after atomization have adroplet dimension in the range from 1 to 10 microns. A plurality ofcapillary conduits through which the liquid is conducted are arranged inthe interior space of the nozzle. The capillary conduits, around which agas stream flows, end in a joint interior mixing space. The end of theinterior mixing space is formed by a nozzle opening.

In the PCT application WO 02/099415 A1, the inventors Paul O'Connor etal. describe the introduction of oil into a laboratory riser reactor bymeans of a high-pressure pump. The PCT application WO 02/099415 A1originates from the Akzo company. The advantage of high-pressureinjection is that a very short contact time, in the present case lessthan 8 seconds, can be achieved when short injection times in the rangeof less than 2 seconds are employed. A nozzle for introduction of feedand fluidizing gas is depicted in FIG. 1 of WO 02/099415 A1. The nozzleis connected to a high-pressure pump. Here, atomization is produced by acontrolled pressure drop of a few hundred bar, by pushing ordepressurizing the fuel through a narrow point. The fuel is thusconveyed through a narrow conduit. The feed is injected via a nozzlewhich is surrounded by a stream of nitrogen.

In the patent application DE 102013019441, the inventors Oliver Schulzet al. describe an atomizer system for two-phase systems with internalmixing. The advantage of the atomizer with mixing chamber is the uniformplanar application of aerosols with particles as opposed to an atomizersystem without mixing chamber.

It is an object of the invention to provide an apparatus and a processby means of which laboratory catalyst testing setups for the catalyticreaction of liquid starting materials can be improved. In particular,the experimental conditions which relate to the reaction of oils such asVGO should be improved. A further object is to provide an apparatuswhich allows improved control in the introduction of liquids.

The objects mentioned here are achieved by provision of an apparatus forspraying liquids, which comprises a needle injector, a liquid supply (5)and a gas supply (4), where the needle injector comprises at least onecapillary line (1) and at least one outer tube (2). In the needleinjector, the internal diameter of each capillary line (1) is in therange of 2-1000 μm, more preferably in the range of 4-500 μm, morepreferably in the range of 5-250 μm, and the capillary line is coaxiallyarranged in the interior space of the respective outer tube (2), thecapillary line (1) is in active communication with the gas supply (4)and the outer tube is in active communication with the liquid supply(5).

In a preferred embodiment, the apparatus of the invention is joined to ahousing, preferably a tubular housing (3), with preference being givento the housing being in active communication with a heating device (6).

The tip (8) of the apparatus is preferably configured in such a way thatthe length difference between the capillary line (1) and the outer tube(2) is in the range of 0-10 mm, with the length difference preferablybeing in the range of 1-5 mm and the capillary line (1) preferably beinglonger than the outer tube (2).

In the apparatus of the invention, the tip (8) of the needle injectordoes not have an internal mixing chamber. The mixture of liquid and gasthus goes directly into the outer region of the needle injector withoutentering a mixing chamber. The absence of a mixing chamber isadvantageous since the configuration of the apparatus without mixingchamber is associated with a smaller engineering outlay than aninjection apparatus equipped with a mixing chamber. In addition, theapparatus of the invention is also very robust.

In addition, preference is given to the apparatus being operated inconjunction with a catalyst testing setup for examining FCC catalystsand/or an aging or impregnation unit for FCC catalysts.

In this preferred embodiment as catalyst testing setup or asimpregnation apparatus, the apparatus according to the invention isconnected to a tubular housing (3).

The invention also provides a process for spraying liquids, which iscarried out by means of the apparatus of the invention, wherein theprocess comprises the following steps:

-   -   (i) controlled introduction of a gas by means of the gas supply        (4) into a capillary line (1),    -   (ii) controlled introduction of a liquid by means of the liquid        supply into the interior space of an outer tube (8),    -   (iii) contacting of the liquid conveyed through the outer tube        (8) with the gas conveyed through the capillary line (1) at the        tip (8) of the apparatus.

Furthermore, in the process for spraying liquids, the liquid which isconveyed through the outer tube (2) has a volume flow in the range of0.1-500 ml/min, preferably in the range of 0.5-250 ml/min, and/or thegas which is conveyed through the capillary line (1) has a volume flowin the range of 10-10,000 ml/min, preferably in the range of 20-2000ml/min.

In a preferred embodiment, the supply or introduction of gases orliquids is carried out with these being heated. For the heating, regionsof the housing, the gas supply and/or the liquid supply are heated, withthe temperature of the gas supply being in the range of 50-300° C.,preferably in the range of 100-250° C.; the temperature of the liquidsupply being in the range from 50 to 300° C., preferably in the rangefrom 100-250° C.; and the temperature of the housing (3) being in therange of 80-700° C., preferably in the range of 100-650° C., morepreferably in the range of 150-550° C.

In the process of the invention, the atomization of the liquid,preferably the oil, is effected without a nozzle. The needle injectorpreferably has a tubular or stump-like tip as shown in FIG. 1. Theneedle injector will hereinafter also be referred to as coaxial needleinjector. In a preferred embodiment, heavy oils such as VGO, HVGO aresprayed by means of the process of the invention.

The longitudinal axis of the coaxial needle injector comprising at leastthe capillary line (1) and the outer tube (2) is preferably arrangedvertically.

In a preferred embodiment, the process of the invention is carried outusing an apparatus in which a plurality of apparatuses (d1, d2, d3, . .. ) for the injection of liquids are installed.

In the process of the invention, the gas is conveyed with a high linearvelocity through the inner tube and at the exit point has a linearvelocity of >170 m/s (i.e. greater than or equal to 170 m/s) given bythe ratio of volume flow to cross-sectional area of the inner tube andis greater than mach 0.5, preferably greater than mach 0.7, inparticular greater than mach 1.0. The mach number is a mathematicalparameter which is derived from the volume flow through thecross-sectional area at the upper end of the capillary (i.e. the exitarea).

The high linear velocity of the gas is an essential element of theprocess of the invention. The high linear velocity can be achieved bythe inner tube being formed by a capillary line. The capillary also hasto be controlled by means of an appropriate admission pressure in orderto convey a sufficient amount of gas through the capillary. Oneparameter of the process of the invention is given by the ratio of thevolume flow of the gas stream to the volume flow of the liquid, with apreferred gas volume flow having a volume flow of 80 ml/min and apreferred liquid volume flow being 5 ml/min. The ratio of gas volumeflow to liquid volume flow is thus 16, the ratio of gas volume flow toliquid volume flow preferably being in the range of 500-1, morepreferably in the range of 10-200, particularly preferably in the rangeof 12-100.

It can be seen from the technical parameters that, in a preferredembodiment of the process of the invention, the very fine mists producedby means of the process have a very low mass flow ratio of gas toliquid. The mass flow ratio of gas to liquid is preferably <0.1, morepreferably the mass flow rate of gas to liquid is <0.04. The mass flowis here reported (by way of example) in kg/h, with the units in thereported mass flow ratio being abbreviated and becoming redundant. Thisprocess aspect or parameter produces a significant difference comparedto the processes described in the prior art. Another advantage here isthat the very fine mists produced have low flows and very small amountsof gases and of liquids are consumed.

It is also possible to use alternative embodiments of capillaries. Theseconsist, for example, of thin tubes which are provided at the ends withorifice plates and micropins. The use of capillaries is, however,particularly preferred. Capillaries having various diameters and lengthscan be purchased. In particular, capillaries having small internaldiameters are also available. In the context of the invention, high gasexit velocities are of great importance and these can be achievedparticularly readily by means of capillaries. For the purposes of thepresent invention, high gas exit velocities are, in particular, exitvelocities which are greater than or equal to mach 1.5, preferablygreater than or equal to mach 2.0. (The mach number is determined asindicated above.)

It should be mentioned that in the process of the invention, the amountof gas which is conveyed through the inner tube is, on a mass basis, 18times smaller than the amount of gas used in coaxial two-phase atomizersas are known in the prior art or are commercially available.

As regards the volume flow, this means that the gas conveyed through theinner tube has a volume which is a factor of 16 smaller than in the caseof the two-phase atomizers known in the prior art. In relation to theprocess of the invention, it can also be said that an importantcharacteristic of the invention is that a spray mist which firstly hasonly a low flow rate and secondly contains an extremely fine dispersionof liquid droplets is produced.

The combination of the apparatus of the invention and the process of theinvention for the injection of oils results, in connection with use inconjunction with agitated catalyst beds, in synergy effects, by means ofwhich particularly homogeneous wetting of the catalyst particles whichcannot be achieved by means of the injectors known from the prior art ismade possible. Furthermore, the use in conjunction with dynamicallyagitated catalyst beds in downcomer tubes or in riser reactors is alsopreferred since in this case improved control of injection is ofcritical interest for the quality of the experimental test data.

With regard to a preferred embodiment of the liquid supply (5), it canbe said that this comprises a pump or a syringe and also a stock vesselwith liquid. Particular preference is given to a liquid supply (5) whichhas a pump. The pump is more preferably a high-pressure pump (forexample an HPLC pump).

In a preferred embodiment, the gas supply (4) comprises a gas supplynetwork and a pressure regulator.

In addition, preference is given to an embodiment in which the liquidsupply (5) and/or the gas supply (4) is connected to a process controlsystem (PCS). The parameters of the process can be controlled orregulated by means of the process control system. The parameters includethe duration of the introduction of the spray mist by means of theapparatus of the invention, the flow rate of the gas stream and the flowrate of the liquid to be metered in. in a preferred embodiment,introduction of the spray mist can be carried out continuously. Inanother embodiment, which is likewise preferred, the introduction can becarried out in the form of metered pulses. Furthermore, continuousintroduction and introduction in pulses can be carried out alternately.

A preferred field of use of the invention relates to use of theapparatus for the injection of oils in connection with laboratorycatalyst testing setups. Particular preference is given to laboratorycatalyst testing setups for testing FCC catalysts; here, the use inconnection with laboratory catalyst testing setups which have anagitated catalyst bed is particularly preferred. Particular preferenceis also given to riser reactors or downcomer tube reactors.

A further preferred field of use of the apparatus of the invention andthe process of the invention is in connection with apparatuses for thecontrolled deactivation of FCC catalysts, in which the catalysts areimpregnated with oils or metal salt solutions under controlledconditions in fluidized beds in heated reaction tubes. These are knownas aging units for catalysts. As metal salt solutions, it is possible touse, for example, vanadium salt solutions or nickel salt solutions. Asan alternative, it is also possible to spray the catalysts withsolutions in which the metals are present in the form of metal-organiccompounds. Wetting of the catalysts under controlled conditions is thuspossible. The organic compounds are removed by burning-off in a thermaltreatment step. Here, it is possible to use temperatures in the range of500-700° C.

Another advantage of the apparatus of the invention is that theformation of carbonaceous material at the end of the liquid outlet isefficiently suppressed. The formation of carbonaceous material in theinjection of oils into reaction spaces which are operated at hightemperatures above 400° C. represents a great technical problem sinceoil injection is either interfered with or completely blocked as aresult. Blocking of the oil injection leads to the study having to bestopped. The apparatus has to be taken apart and cleaned.

Here, it should also be noted that the apparatus of the invention andthe process of the invention can have different configurations dependingon the field of use, i.e. use in metal impregnation or use in laboratoryFCC catalyst testing apparatuses. The reason is that apparatuses formetal impregnation are generally charged with relatively large amountsof catalyst. The individual impregnation tubes have a catalyst charge inthe range from 50 to 200 g. It is in such a case frequently necessary tospray a relatively large amount of liquid into the reaction space andonto the catalyst. It is therefore possible for a plurality of injectionapparatuses according to the invention to lead into a single reactor.For example, a single reaction tube can be equipped with from two to sixapparatuses according to the invention for the injection of oils. Theindividual apparatuses can, depending on the configuration of the agingapparatus, all spray feed liquid into the impregnation tubes at the sametime or be operated individually.

The configuration of the openings is not restricted to a single coaxialor circular arrangement of the capillary line in the interior space andthe liquid-conveying line as outer tube. It is also possible for two ormore capillary lines to be located in the interior space of the outerline (2) (see FIG. 2.b). The capillary can likewise have differentgeometric shapes. Apart from a round or elliptical cross-sectional area,it is also possible for the capillary lines to have, for example, ahexagonal shape, a square shape or a triangular shape. Embodiments ofthese types are shown in FIG. 2.c. The length of the capillary can befrom a few millimeters up to a number of meters. The length of thecapillary line is preferably in the range of 1-150 cm; preference isalso given to a length in the range of 3-100 cm, particularly preferablya length in the range of 3-20 cm. The capillary lines are preferablymade of metal, steel, glass, silica, ceramic, plastic. Particularlypreferred materials are steel or fused silica.

Another characteristic of the process of the invention is thatreagglomeration or coagulation of the atomized liquid droplets is verylow.

The process of the invention can be used for the atomization of bothlow-viscosity liquids and high-viscosity liquids.

It may be mentioned here that the high-viscosity liquids (i.e. liquidshaving a low flowability) have a significantly better tendency to formdroplets than low-viscosity liquids (i.e. liquids having a highflowability). For example, water has a viscosity at 20° C. of 1.001mPa*s and dodecane has a viscosity of 1.520 mPa*s. In connection withthe process of the invention, dodecane thus has a higher tendency toform droplets than water.

Use in the FCC Sector

Preference is given to using the apparatus of the invention and theprocess of the invention for the injection of oils in combination withcatalyst testing setups for testing FCC catalysts. It is particularlyadvantageous that the process is very easy to control; in FCC tests,precise control of the introduction of feed fluid or the introduction ofoil is of great importance, especially the introduction of amounts inthe range from 0.1 to 50 g/min, preferably 0.5-10 g/min.

The catalyst has a temperature in the range from 600° C. to 800° C.,while the temperature of the feed liquid is in the range of 50 to 300°C., preferably in the range from 100 to 250° C. An upper temperaturelimit is imposed by thermal cracking of the liquids otherwise occurring,which has an adverse effect on the tests. A particular minimumtemperature is necessary, in particular, when the oils have to beliquefied first.

The temperature in the reaction space of the catalyst testing setup is550° C., with the oil, which is, for example, preheated to 250° C.,being injected under controlled conditions into the reaction space. Itshould be noted that the process of the invention is much better forachieving very homogeneous mixing of the oil droplets and the catalystparticles at this point so that they can react under controlledconditions. The apparatus of the invention and the process of theinvention result in the oil being atomized very finely and the atomizedoil being able to be brought into intimate contact with the catalystwithin a few milliseconds. Here, the oil is also heated, for example inthe present case to 550° C. The processes of atomization of the oil andwetting of the catalyst with oil proceed simultaneously.

EXAMPLES

I. To illustrate the apparatus of the invention and the process of theinvention, an apparatus corresponding to the schematic depiction shownin FIG. 1 was constructed. To produce the needle injector, a fusedsilica capillary having an internal diameter of 50 μm and a length of 30cm was introduced into a 1/16″ steel tube ( 1/16″ external diametercorresponds to an internal diameter of 1.387 mm since the steel tube hasa wall thickness of about 0.1 mm) of the same length. A gas supply wasconnected to an end piece of the fused silica capillary and a liquidsupply was connected to an end piece of the steel capillary. Theinjector equipped with gas supply and liquid supply was positionedvertically in a holder in which the tip of the needle injector wasarranged 8 cm above a plate. A rectangular paper strip (4 cm×10 cm) wasplaced on the upper side of the plate underneath the tip of the needleinjector. Gas and liquid were conveyed in a controlled manner throughthe needle injector by means of the gas supply and the liquid supply.The liquid supply was 5 ml/min and the gas supply was 80 ml/min. Sprayinjections were carried out by means of the apparatus. An intrinsicallystable spray mist was produced on exit of the fluids from the ends ofthe tubes at the tip of the needle injector. The spray mist wascollected on the paper strip which had been placed underneath theinjector. Ink (a colored aqueous solution) was used as liquid for thespray experiments. In the region underneath the exit opening of theinjector needle, a spray mist having a conical shape was observed. Noshape changes were to be seen over an observation period of 10 minutes.The spray cone thus had a constant shape. FIG. 3 shows a photo of aspray cone which has an opening angle of 14°. Individual droplets arebelow the optical resolution limit and cannot be seen. The stability ofthe very fine mist enables a droplet size of from 10 μm to 20 μm to beconcluded.

II. Supporting of an Organic Dye to Produce a Pigment

To illustrate the process of the invention, a pulverulent solid whichconsisted of an aluminum oxide-comprising support oxide from Alcoa wascoated with eosin-comprising ink. The aluminum oxide-comprising supportoxide was an FCC catalyst material which had been produced by means of aspray dryer from a spraying suspension, in which the initial componentswere present. The eosin-comprising red ink was dissolved in acetone,employing a volume ratio of 1:10 (i.e. 1 part of ink to 10 parts ofacetone). Eosin is tetrabromofluorescein or the disodium salt of2′,4′,5′,7′-tetrabromo-3′,6′-dihydroxyspiro[2-benzofuran-3,9′-xanthen]-1-one.The concentration of eosin dye (tetrabromofluorescein) in the ink was 1mol/l. The aluminum oxide-comprising support oxide had an averageparticle size of 85 μm, with the size distribution of the particlesbeing in the range 50-120 μm, so that the particles could be broughtinto the fluidized state by means of a gas stream. The pulverulentaluminum oxide (250 g) was introduced into a heated reaction tube whichwas provided with an injector according to the invention. The diameterof the reaction tube was 6 mm, and the length was 1 m. The reaction tubewas maintained at 80° C. A gas stream was introduced via feed nozzlesinto the reaction tube, as a result of which the pulverulent aluminumoxide was brought into the fluidized state. While the fluidized aluminumoxide was stored at 80° C. in the feed vessel, spray injection of theeosin solution was carried out for a time of 60 seconds, with theinjection being carried out at a flow rate of 10 ml/min. Thus, 10 ml ofeosin-acetone solution were injected. In the present case, 250 g perminute of the pulverulent support material were coated under controlledconditions with the dye by means of the apparatus of the invention andthe process of the invention. The reaction time or the coating time wascarried out in a few milliseconds, with the acetone being separated offdirectly via the gas phase. (The residence time in the reaction tube wasin the range of 2-6 seconds.) The residence time is determined from thegas flow and the proportion of hydrocarbon which is vaporized. Thevaporized proportion of hydrocarbon thus increases the volume of the gasstream. In the present case, acetone as solvent for the eosin-comprisingdye was vaporized in the reaction tube. The red-coated support wascollected downstream of the reaction tube. Analysis of the coatedsupport material indicated that a very uniform and homogeneousdistribution of the dye on the individual particles was present.

This process of the invention is, apart from the discontinuous operationpresented, suitable for being operated continuously and is thereforeparticularly suitable for carrying out, for example, supporting on asemiindustrial scale. In the case of continuous operation of theapparatus described in the example, an amount of catalyst of 360 kg/daycan be impregnated or coated under the conditions presented here bymeans of the process of the invention. To carry out the processcontinuously, the apparatus components for introduction of catalyst, thecatalyst receptacle and the reservoir for the impregnation solution hadto be appropriately enlarged and adapted. In the apparatus describedhere, up to 500 kg/day of material can be reacted or treated afterappropriate adaptation of the apparatus. In a further embodiment of theapparatus of the invention, the reaction tubes can also be arranged inparallel. In this way, the process can be operated in an even moreefficient way since both the high accuracy of the process for coating orimpregnation can be utilized and the advantageous configurationalpossibilities of the apparatus can lead to improved efficiency inoperation of the apparatus. Two or more parallel reaction tubes whichare provided in conjunction with a joint reservoir for impregnation orcoating fluid are advantageous. For example, the apparatus of theinvention can, in one embodiment having four reaction tubes arranged inparallel can be used for coating an amount of catalyst of 1.4-2 metrictons per day. Advantages are that the apparatus can have only smalldimensions with a reaction tube having a length of one meter and adiameter of 6 mm and the process can be carried out in a short time. Atthe dimensions of the reaction tube indicated in the example and basedon the density of the aluminum oxide of 4 g/cm, from 40 g/min to 250g/min of material can be coated in this way. In the field of specialtychemicals, daily productions of 1-2 metric tons per day can represent anamount which is of great economic importance.

The embodiments of the apparatus of the invention presented here are notto be interpreted as exhaustive or limiting in any way. In a furtherembodiment of the apparatus, two or more reaction tubes can be connectedin series, with different impregnation or coating solutions beingapplied to the catalyst material or support material being passedthrough.

BRIEF DESCRIPTION OF THE FIGURES:

FIG. 1 schematically shows the apparatus of the invention for sprayingliquids having a capillary line (1) and outer tube (2), with theapparatus being arranged in a tubular housing (3). The tubular housingis surrounded by a heating device (6).

FIG. 2.a schematically shows the cross section through the injector ofthe apparatus of the invention, with the injector having a capillaryline (1) and an outer tube (2).

FIG. 2.b schematically shows the cross section through the injector ofthe apparatus of the invention, with the injector having two differentcapillary lines (1′) and (1′) and also an outer tube (2).

FIG. 2.c schematically shows the cross sections of variously configuredcapillary lines having a hexagonal shape (1″), a square shape (1′″) anda triangular shape (1″″).

FIG. 3 shows a photograph of the injector tip (8) in the operatingstate, with a colored solution being sprayed by means of the apparatusof the invention. The spray cone has an opening angle of 14°. Individualdroplets cannot be resolved optically.

FIG. 4 schematically shows the apparatus of the invention for sprayingliquids in an arrangement having a plurality of apparatuses. In thepresent case, the apparatuses for spraying liquid are used in a setupfor impregnating catalysts, with the setup having three apparatuses (d1,d2, d3) at the top and two lateral apparatuses (d4, d5).

LIST OF REFERENCE NUMERALS

1, 1′, 1″—capillary line in various configurations

. . .

2—outer tube for liquid supply/oil supply

3—housing

4—gas supply

5—liquid supply

6—heating device

8—injector tip

9—contact space, reaction space

12—flow direction

13—joint liquid supply for injectors d1, d2, d3

14—joint gas supply for the injectors d1, d2, d3

15—gas supply for fluidizing gas

16—screen or frit for screening the gas feed lines

d1, d2, d3—vertically arranged injectors, top of the setup

d4, d5—laterally arranged injectors, longitudinal axis of the injectorshas a tilt angle relative to the vertical axis, tilt angle is <40°,preferably <30°, more preferably <25°

1. An apparatus for spraying liquids, which comprises a needle injector,a liquid supply and a gas supply, wherein the needle injector comprisesat least one capillary line and at least one outer tube and the internaldiameter of each capillary line of the needle injector is in the rangeof 2-400 μm, and the capillary line is coaxially arranged in theinterior space of the respective outer tube, the capillary line is inactive communication with the gas supply and the outer tube is in activecommunication with the liquid supply.
 2. The apparatus for sprayingliquids according to claim 1, wherein the apparatus is joined to ahousing.
 3. The apparatus for spraying liquids according to claim 1,wherein a tip of the apparatus is configured in such a way that a lengthdifference between the capillary line and the outer tube is in the rangeof 0-10 mm.
 4. The apparatus for spraying liquids according to claim 1,wherein the apparatus is configured for operation in conjunction with acatalyst testing setup for examining FCC catalysts and/or an aging orimpregnation unit for FCC catalysts.
 5. A process for spraying liquidswith the apparatus of claim 1, wherein the process comprises: (i)controlled introduction of a gas via the gas supply into a capillaryline, (ii) controlled introduction of a liquid via the liquid supplyinto an interior space of an outer tube, and (iii) contacting of theliquid conveyed through the outer tube with the gas conveyed through thecapillary line at a tip of the apparatus.
 6. The process for sprayingliquids according to claim 5, wherein the liquid which is conveyedthrough the outer tube has a volume flow in the range of 0.1-10 ml/min,and/or the gas which is conveyed through the capillary line has a volumeflow in the range of 10-300 ml/min.
 7. The process for spraying liquidsaccording to claim 5, wherein the housing, the gas supply and/or theliquid supply are heated, with the temperature of the gas supply beingin the range of 50-300° C.; the temperature of the liquid supply beingin the range from 50 to 300° C; and the temperature of the housing beingin the range of 80-700° C.
 8. The process for spraying liquids accordingto claim 5, comprising spraying a heavy oil.
 9. The process for sprayingliquids according to claim 5, comprising spraying an oil, wherein theoil is introduced in pulses or continuously and the pulses have aduration in the range of 1-400 seconds.
 10. The process for sprayingliquids according to claim 5, wherein the needle injector comprising thecapillary line and the outer tube is arranged vertically.
 11. Theprocess for spraying liquids according to claim 5, wherein a very finemist is produced by the process, having a mass flow ratio of gas toliquid of <0.1.
 12. The process for spraying liquids according to claim5, wherein the process is controlled by a PC.